Fuse.



N0. 808,200. PATENTED DEC. 26. 1905 J. B. GRAYBI'LL.

FUSE.

APPLICATION FILED MAR.22. 1905.

Witmwoeo J Maz 7 %g 4 E I 4 PATENT OFFICE.

JOHN E. GRAYBILL, OF YORK, PENNSYLVANIA.

FUSE.

Specification of Letters Patent.

Patented Dec. 26, 1905.

Application filed March 22, 1905. Serial No. 251,505.

T0 at whom, it may concern:

Be it known that I, JOHN E. GRAYBILL, a citizen of the United States,residing at York, in the county of York and State of Pennsylvania, haveinvented certain new and useful Improvements in Fuses, of which thefollowing is a specification.

This invention relates to means for protecting electric circuits, whichconsists in a fusible strip which is inserted in the circuit to beprotected, the strip being chosen of such dimensions and material thatit will fuse, and thereby open the circuit at a current below that atwhich apparatus connect ed in the circuit would be damaged.

The practical application of devices of the character thus described iswell understood in the art.

The present invention relates more particularly to the type ofprotecting devices known as inclosed fuses, but is not necessarilylimited thereto in all of its aspects.

The object of the invention is to provide an improved protecting deviceof the character described, which can best be set forth in connectionwith the accompanying drawings, of which- Figure 1 is a plan view,partly broken away, of an inclosed fuse. Fig. 2 is a longitudinalsection on the line a I) of Fig. 1, and Fig. 3 is a perspective view ofa detail.

Referring to the drawings, the improved fuse comprises a casing 1, whichmay be of any suitable insulating material. It is preferable that thiscasing shall be transparent, so that the condition of the interior maybe observed. To the ends of the casing 1 are secured in any suitablemanner electrical conducting-caps 2 and 3, which may be of brass orother suitable material. These caps constitute the terminals of thefuse, and to them is secured at its ends the fusible strip 4, so thatelectrical contact is established be tween the two terminals. Within thecasing arealso two longitudinally-movable members 5 and 6, which attheir ends nearest the terminals have enlarged portions 7 and 8, whichfit with easy clearance within the easing 1. Channels 9 and 10 for thepassage of the fusible strip 4 are out in the enlarged portions, thesechannels being located out of line with the points of attachment of thefusible strip to the terminals, so that this strip is given a directionparallel to the face of the terminal at each end. The other ends of themembers 5 and 6that is, those ends which are not adjacent to theterminals consist in offset forks 11 and 12. The shoulders 13, formed atthe offsets upon the two members, are adapted to engage with each otherto prevent relative longitudinal movement of the members and are held inengagement by the fusible strip 4, which, it will be seen, passes uponopposite sides of the two members and between the tines of their forks.

Means for causing relative longitudinal movement of the members mayconsist in a spring 14:, bearing against the end of one member, as 5,and against a plate 15, preferably of insulating material,which has achannel 16 for the passage of the fusible strip, which channel is inline with the channel 9 in its adjacent member 5. The fusible strip istherefore given a direction at this end parallel to the face of theterminal 3, and the spring 14 operates to press the ends of the fuseagainst both the terminals.

In the positions shown the fusible strip is intact and the parts are inoperative positions. If now an excessive current flows through thefusible strip, the strip will be melted. The members 5 and 6 being nolonger restrained by the fusible strip will have relative longitudinalmovement under the influence of the spring 14, when the forked ends ofthe members will ride upon each other, there being provided sufficientclearance within the casing at this point to permit it. The openingsbetween the tines through which the fusible strip formerly passed willbe closed, thus breaking the arc, and the ends of the members willsubstantially fill the easing at this point, thus rapidly cooling thearcing-space.

The blowing of the fuse at a point adjacent to the forked ends of themembers may be brought about by reducing the cross-section of thefusible strip or in any other suitable manner.

WVhile I have described my invention in what I consider its bestembodiment, it will be understood that it may have other embodiments,and should not, therefore, be limited to the construction shown.

What I claim, and desire to secure by Letters Patent, is

1. The combination with a terminal, of a fusible strip connectedthereto, a member having a channel for the passage of said strip, saidchannel being out of line with the point of connection of said fusiblestrip to said terminal, and means for pressing said member toward saidterminal, substantially as described.

2. In an inclosed fuse, the combination With a casing, of terminals, afusible strip within said casing, having its ends connected to saidterminals, longitudinally-movable members within said casing, saidmembers having channels through which said strip passes, said channelsbeing out of line with the points of connection of said strip to saidterminals, and means for forcing said members toward said terminals,substantially as described.

3. In an inclosed fuse, the combination with a casing, oflongitudinally-movable members therein, means tending to cause relativelongitudinal movement thereof, the ends of said members being adapted toengage to prevent such movement, and a fusible strip holding saidmembers in engagement, there being clearance between said casing and theengaging ends of said members so that the said ends of the members mayride upon each other to fill the arc-gap upon relative longitudinalmovement, substantially as described.

4. In an inclosed fuse, the combination with a casing, of a terminal ateach end thereof, of a fusible strip within said casing and secured atits ends to said terminals, longitudinally-movable members within saidcasing, said fusible strip passing along one side of one of said membersand along the opposite side of another of said members, and means forcausing relative longitudinal movement of said members, substantially asdescribed.

5. In an inclosed fuse, the combination with a casing, of a terminal ateach end, longitudinally-movable members therein, a fusible stripconnected to said terminals within said casing, extending along saidmembers and holding them in engagement, a plate having a channel for thepassage of said fusible strip, which channel is out of line with thepoint of connection of said fusible strip with the one of said terminalsadjacent to said plate, and a spring interposed between said plate andone of said members, the other of said members bearing against the otherend of said casing, substantially as described.

6. In an inclosed fuse, the combination with a casing, of a fusiblestrip therein, longitudinally-movable members within said casing, eachof said members comprising an offset fork, the shoulder formed at theoffset of one member being adapted to bear against the like shoulderupon the other of said members, said fusible strip passing alongopposite sides of said members and between the tines of said forks, andmeans for causing relative longitudinal movement of said members,substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JOHN E. GRAYBILL.

lNitnesses A. E. I-IAUsMANN, Tnos. HOWE.

